In the UMTS (Universal Mobile Telecommunications System) network, the specifications of long term evolution (LTE) have been drafted for the purpose of further increasing high speed data rates, providing lower latency and so on (see non-patent literature 1). In addition, successor systems of LTE (referred to as, for example, LTE-A (LTE-Advanced), FRA (Future Radio Access), 5G (5th generation mobile communication system), 5G+(5G plus), New-RAT (Radio Access Technology) and so on) are also under study for the purpose of achieving further broadbandization and increased speed beyond LTE.
In existing LTE systems (for example, Rel. 8), a user terminal (UE: User Equipment) can assume that, in the downlink (DL), a DL data channel is transmitted with constant transmission power. The user terminal demodulates the DL data channel (for example, PDSCH (Physical Downlink Shared CHannel)) using a cell-specific reference signal (CRS) (which is common to user terminals in a cell). The CRS is transmitted with constant transmission power, so that, by transmitting the DL data channel with constant transmission power (for example, with the same transmission power as that of the CRS, or with a predetermined power gap), it is possible to demodulate the DL data channel using the CRS (especially when a modulation scheme, in which the amplitude of received signals provides information, such as 16QAM (Quadrature Amplitude Modulation), 64QAM and others, is used).